Analysis of liquid-liquid distribution constants of organophospohorus based extractants

Dialkylorganophosphorus based acids in two-phase liquid systems are reasonably well described by the dependence of their dissociation and distribution constants on the ionic strength of the aqueous phase, the property parameters of solvents and structural properties of alkyl and alkoxyl substituents, respectively. The satisfactory results have also been obtained for the distribution constants of trialkylphosphine oxides influenced by the properties of solutes, solvents and ionic strength of the aqueous phase, respectively. The analysis of solvent effects upon the distribution constants of neutral esters of organophosphorus based acids has been performed for five solutes only, all of the low hydrophobicity, i.e. the first four members of homologous series of trialkyl esters of phosphoric acid and dimethyl methylphosphonate, respectively.